security-keys: CVE-2014-9529

Fixes memory corruption or panic during key garbage collection

Reference:
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-9529

Signed-off-by: Sona Sarmadi <sona.sarmadi@enea.com>

2 files changed, 54 insertions, 0 deletions

diff --git a/recipes-kernel/linux/files/security-keys-CVE-2014-9529.patch b/recipes-kernel/linux/files/security-keys-CVE-2014-9529.patch
new file mode 100644
index 0000000..573b530
--- /dev/null
+++ b/recipes-kernel/linux/files/security-keys-CVE-2014-9529.patch
@@ -0,0 +1,53 @@
+From a7033e302dcd38bb4333f46b3fdcd930955e402d Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sasha.levin@oracle.com>
+Date: Mon, 29 Dec 2014 09:39:01 -0500
+Subject: [PATCH] KEYS: close race between key lookup and freeing
+
+commit a3a8784454692dd72e5d5d34dcdab17b4420e74c upstream.
+
+When a key is being garbage collected, it's key->user would get put before
+the ->destroy() callback is called, where the key is removed from it's
+respective tracking structures.
+
+This leaves a key hanging in a semi-invalid state which leaves a window open
+for a different task to try an access key->user. An example is
+find_keyring_by_name() which would dereference key->user for a key that is
+in the process of being garbage collected (where key->user was freed but
+->destroy() wasn't called yet - so it's still present in the linked list).
+
+This would cause either a panic, or corrupt memory.
+
+Fixes CVE-2014-9529.
+
+Upstream-Status: Backport
+
+Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
+Signed-off-by: David Howells <dhowells@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Signed-off-by: Sona Sarmadi <sona.sarmadi@enea.com>
+---
+ security/keys/gc.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/security/keys/gc.c b/security/keys/gc.c
+index d67c97b..7978186 100644
+--- a/security/keys/gc.c
++++ b/security/keys/gc.c
+@@ -201,12 +201,12 @@ static noinline void key_gc_unused_keys(struct list_head *keys)
+                if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
+                        atomic_dec(&key->user->nikeys);
+ 
+-               key_user_put(key->user);
+-
+                /* now throw away the key memory */
+                if (key->type->destroy)
+                        key->type->destroy(key);
+ 
++               key_user_put(key->user);
++
+                kfree(key->description);
+ 
+ #ifdef KEY_DEBUGGING
+-- 
+1.9.1
+
diff --git a/recipes-kernel/linux/linux-qoriq_3.12.bb b/recipes-kernel/linux/linux-qoriq_3.12.bb
index e7af627..f082b04 100644
--- a/recipes-kernel/linux/linux-qoriq_3.12.bb
+++ b/recipes-kernel/linux/linux-qoriq_3.12.bb
@@ -36,6 +36,7 @@ SRC_URI = "git://git.freescale.com/ppc/sdk/linux.git;nobranch=1 \
     file://0003-shmem-CVE-2014-4171.patch \
     file://fs-CVE-2014-4014.patch \
     file://tracing-CVE-2014-7825_CVE-2014-7826.patch \
+    file://security-keys-CVE-2014-9529.patch \
 "
 SRCREV = "6619b8b55796cdf0cec04b66a71288edd3057229"